def self.source_info
          {
              base_url: 'http://www.mycancergenome.org/',
              citation: 'Jain,N., Mittendorf,K.F., Holt,M., Lenoue-Newton,M., Maurer,I., Miller,C., Stachowiak,M., Botyrius,M., Cole,J., Micheel,C., et al. (2020) The My Cancer Genome clinical trial data model and trial curation workflow. J. Am. Med. Inform. Assoc., 27, 1057–1066. PMID: 32483629',
              site_url: 'http://www.mycancergenome.org/',